Closed circulating cooling water system

Abstract

The invention relates to a closed circulating cooling water system, which belongs to the technical field of industrial closed circulating cooling water systems, and comprises a circulating cooling water pump, a water-air heat exchanger, a filter, a cooled device and a degassing tank which are sequentially connected through pipelines, and the pipeline between the degassing tank and the circulating cooling water pump is additionally connected with a nitrogen pressure stabilizing system. The circulating cooling water system provided by the invention is high in reliability and high in integration level, and adopts closed circulation; the field installation is simple, the operation and maintenance are convenient, cooling water meeting the use requirements can be provided for the distributed water-air cooling phase modifier, and the safe and efficient operation of the phase modifier equipment is ensured.

Description

Technical Field

[0001] The invention relates to a circulating cooling water system suitable for a distributed water-air cooling phase regulator, belonging to the technical field of industrial closed-loop circulating cooling water systems. Background Art

[0002] The new distributed water-air cooled phase regulator is one of the key technologies in the field of modern renewable energy, especially in wind power and photovoltaic power generation. These power stations are often located in areas with scarce water resources. Therefore, for these phase regulators, the design of a closed-loop cooling water system is not only a technical advantage, but also the key to their stable operation in these harsh environments.

[0003] The design principle of the closed-loop cooling water system is to ensure that the system has sufficient cooling capacity to adapt to various environmental conditions and ensure effective cooling of the phase regulator. The design and implementation of this system is crucial to maintaining the stability of the phase regulator and extending its service life. It not only needs to meet the requirements of technical parameters, but also consider various challenges in practical applications to meet the cooling needs of distributed water-air cooled phase regulators under extreme climatic and geographical conditions. Summary of the invention

[0004] The purpose of the invention is to solve the technical problem of how to configure a stable and reliable closed-loop cooling water system for a distributed water-air cooled phase regulator.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the present invention provides a closed-loop cooling water system, including a circulating cooling water pump, a water-to-air heat exchanger, a filter, a cooled device, and a degassing tank connected in sequence through pipelines, the degassing tank is connected to the circulating cooling water pump pipeline to form a circulation, and the pipeline between the degassing tank and the circulating cooling water pump is further connected to a nitrogen pressure stabilizing system.

[0006] Preferably, an antifreeze solution containing ethylene glycol is used as the cooling medium.

[0007] Preferably, the nitrogen pressure stabilization system includes a water replenishment interface, an expansion tank, and a nitrogen cylinder connected in sequence. The nitrogen cylinder is used to fill the expansion tank with high-purity nitrogen at a stable pressure, thereby maintaining a constant pressure in the pipeline and filling the cooling medium, and buffering the volume change of the cooling water caused by temperature changes.

[0008] Preferably, the number of the circulating cooling water pumps is two, and they are interlocked and connected in parallel.

[0009] Preferably, flexible joints are provided at the inlet and outlet of the circulating cooling water pump for vibration reduction.

[0010] Preferably, an automatic exhaust valve is provided on the top of the degassing tank to completely exhaust the gas in the cooling water; and the degassing tank is provided with an electric heater for increasing the temperature of the cooling water when the ambient temperature is low.

[0011] Preferably, the water-to-air heat exchanger is provided with a variable frequency fan and multiple groups of industrial frequency fans, which can control the start and stop of the fans according to the inlet water temperature of the cooled device under different ambient temperatures and heat exchange conditions.

[0012] Preferably, it comprises a pressure / differential pressure monitoring device for monitoring the pressure of the expansion tank, the outlet pressure of the circulating water pump, and the differential pressure of the filter, and a level monitoring device for monitoring the liquid level of the expansion tank.

[0013] Preferably, a circulating water flow monitoring device is included for monitoring each of the cooled components.

[0014] Preferably, it includes a temperature monitoring device for monitoring the inlet and return water temperatures of the main pipe and the return water temperature of each of the cooled devices.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The circulating cooling water system provided by the present invention has high reliability, high integration, and adopts a closed cycle; it is simple to install on site, convenient to operate and maintain, and can provide cooling water that meets the use requirements for the distributed water-air cooled phase regulator, thereby ensuring the safe and efficient operation of the phase regulator equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the flow chart of the circulating cooling water system for the distributed water-air cooled phase regulator.

[0018] Figure numerals: 1. Circulating water supply device; 2. Water-to-air heat exchanger; 3. Circulating cooling water pump 1; 4. Circulating cooling water pump 2; 5. Filter; 6. Degassing tank; 7. Electric heater; 8. Nitrogen bottle; 9. Expansion tank; 10. Water supply interface; 11. Liquid level transmitter; 12. Pressure transmitter 1; 13. Pressure transmitter 2; 14. Pressure transmitter 3; 15. Pressure differential switch; 16. Thermal resistor 1; 17. Thermal resistor 2; 18. Flow meter 1; 19. Flow meter 2; 20. Flow meter 3; 21. Flow meter 4; 22. Thermal resistor 3; 23. Thermal resistor 4; 24. Thermal resistor 5; 25. Thermal resistor 6. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The embodiment of the present invention discloses a closed-loop cooling water system suitable for distributed water-air cooled phase shifters. The core components of the system include a circulating water supply device 1, a water-air heat exchanger 2, a cooling medium, and a power distribution system required for the cooling system. The system is designed to ensure that the phase shifter equipment can operate safely and efficiently under various environmental conditions. With its high reliability, high integration, and closed-loop design, the system simplifies on-site installation and operation and maintenance work, and meets the requirements of distributed water-air cooled phase shifters for the use of cooling water.

[0021] The circulating water supply device 1 is further subdivided into a circulating cooling water pump 1 3, a circulating cooling water pump 2 4, a filter 5, a nitrogen pressure stabilizing system, a degassing tank 6, an electric heater 7, a piping system, instruments and meters, etc.

[0022] The core power source of this system is the circulating cooling water pump 1 3 and the circulating cooling water pump 2 4, which together provide the necessary power for the circulation of the circulating cooling water system. The circulating cooling water pump 1 3 and the circulating cooling water pump 2 4 are interlocked and standby with each other, and are connected in parallel to ensure the continuous operation of the system. When the outlet pressure of one of the water pumps is low, the system will automatically switch to the other water pump. At the same time, flexible joints are set at the inlet and outlet of the water pump to reduce vibration.

[0023] These circulating water pumps are horizontal centrifugal pumps with mechanical seals and are made of stainless steel 304 to adapt to the liquid environment. The system is designed with one pump working and one pump on standby. Each pump can provide 100% capacity and is equipped with over-current and overheating protection measures. This design enables the pump group to operate continuously under different operating conditions without manual supervision. The working flow design range of the pump is wide, and it can operate smoothly between 50% and 120% of the normal operating point, ensuring the flexibility and adaptability of the system. In order to reduce vibration, flexible joints are specially set at the inlet and outlet of the pump to reduce vibration.

[0024] The function of the filter 5 is to ensure that the cooling medium remains clean, thereby improving the working efficiency and reliability of the system; the filter 5 uses a stainless steel filter element with a standard mesh and small water resistance, and the material is 304; preferably, a Y-type circulating water filter with a bypass can be used, which can be repaired online. The degassing tank 6 is located at the inlet of the main circulating cooling loop water pump, and an automatic exhaust valve is provided on the top to completely exhaust the gas in the cooling water; the degassing tank 6 is also provided with an electric heater 7, which is mainly used to increase the temperature of the cooling water in the extremely low temperature in winter or when the phase regulator is shut down to prevent the water temperature in the cooler from being too low.

[0025] The function of the nitrogen pressure stabilization system is to maintain the stability of the pressure in the pipeline and ensure that the cooling medium always fills the pipeline. At the same time, it can also buffer the changes in the volume of cooling water caused by temperature changes, thereby ensuring the stable operation of the system. The nitrogen pressure stabilization system includes a nitrogen bottle 8, a nitrogen pipeline and an expansion tank 9. The top of the expansion tank 9 is filled with high-purity nitrogen with a stable pressure. This design is crucial to maintaining the constant pressure in the pipeline. It not only ensures that the cooling medium can fully fill the pipeline, but also effectively buffers the changes in the volume of cooling water caused by temperature changes. When the cooling medium is reduced due to a small amount of exudation, the nitrogen in the expansion tank 9 will automatically expand and press the cooling medium into the circulation pipeline system, thereby maintaining the stability of the pressure in the pipeline and the sufficiency of the cooling medium. In addition, the expansion tank 9 also has a buffering function, which can cope with the changes in the volume of cooling water caused by temperature changes and ensure the stability of the system operation.

[0026] Water-to-air heat exchanger 2 is another key component in the system. It is responsible for cooling the cooling medium to ensure that the cooled equipment can receive water at a suitable temperature. Water-to-air heat exchanger 2 is equipped with variable frequency fans and multiple sets of industrial frequency fans. The start and stop of these fans are controlled by the DCS according to the instructions issued by the temperature sensor to control the water temperature and achieve energy saving. The cooling medium uses antifreeze containing ethylene glycol to prevent the pipes from freezing at extremely low outdoor ambient temperatures. In addition, the main equipment of water-to-air heat exchanger 2 also includes coils and heat dissipation fins.

[0027] In addition, the system is also equipped with a series of monitoring equipment to monitor the operating status of the circulating cooling water system in real time. These equipment include pressure / differential pressure monitoring devices for the expansion tank 9 pressure, circulating cooling water pump outlet pressure, and pressure difference before and after the filter 5; temperature monitoring devices for monitoring the main pipe inlet and return water temperatures and the return water temperature of each cooled equipment; circulating water flow monitoring devices for monitoring each cooled equipment; and liquid level monitoring devices for monitoring the liquid level of the expansion tank 9.

[0028] Specifically, the expansion tank 9 is equipped with a liquid level transmitter 11, which is used to monitor the liquid level of the expansion tank 9, and to issue a high, low or leakage alarm when the operating condition is abnormal. The outlets of the circulating cooling water pump 1 3 and the circulating cooling water pump 2 4 are respectively equipped with a pressure transmitter 1 12 and a pressure transmitter 2 13, which are used to monitor the pressure parameters of the pump outlet, and to issue a high / low alarm of the pump outlet pressure when the operating condition is abnormal. The nitrogen cylinder 8 is also equipped with a pressure transmitter 3 14, which is used to monitor the pressure of the nitrogen in the tank, and to issue a high or low nitrogen pressure alarm when the operating condition is abnormal. The same differential pressure switch 15 is connected to the front and back of the filter 5 at the same time, which is used to monitor the pressure difference before and after the filter 5, and to issue a high differential pressure alarm of the filter 5 when the operating condition is abnormal.

[0029] The circulating cooling water inlet and return main pipes are respectively equipped with thermal resistor 16 and thermal resistor 2 17 for monitoring the temperature of the cooling medium in the inlet and return main pipes and issuing an alarm for high temperature of the cooling medium in the inlet and return main pipes when the working conditions are abnormal.

[0030] The return pipe section of each cooled device is respectively equipped with thermal resistor 3 22, thermal resistor 4 23, thermal resistor 5 24 and thermal resistor 6 25, which are used to monitor the temperature of the cooling medium of the return pipe section of each cooling device, and issue a high temperature alarm of the cooling medium of the corresponding pipe section when the working condition is abnormal. The cooling medium inlet of each cooled device is equipped with flow meter 1 18, flow meter 2 19, flow meter 3 20 and flow meter 4 21, which are used to monitor the water inlet flow of each cooled device.

[0031] The main working principle of the closed-loop cooling water system provided by the present invention is as follows:

[0032] During normal operation, the circulating cooling water pump 1 3 or the circulating cooling water pump 2 4 will be started. First, the cooling medium will be processed by the water-to-air heat exchanger 2 and the filter 5, and then sent to each cooled device for heat exchange. After the heat exchange is completed, the cooling medium will flow through the degassing tank 6 and return to the circulating cooling water pump 1 3 or the circulating cooling water pump 2 4 under the pressure stabilization of the expansion tank 9, ready for the next cycle. The water replenishment of the circulating cooling water system is completed through the water replenishment interface 10 in the nitrogen pressure stabilization system.

[0033] During normal operation, the cooling medium will be filtered for impurities through a Y-type circulating water filter 5, which is provided with a bypass to support online maintenance. At the same time, the fan start-stop group of the water-to-air heat exchanger 2 is feedback-controlled by the DCS according to the temperature sensor 16.

[0034] The present invention provides a stable and reliable closed-loop cooling water system, which has at least the following main functions:

[0035] 1. The system uses circulating cooling medium as heat exchange medium to perform heat exchange in the air cooler of the phase modulator body, the oil cooler of the lubricating oil system and the collector ring cooler. Specifically, it completes the heat exchange between the heat exchange medium and the cooling medium of the circulating water system inside these devices, and transfers the absorbed heat to the external environment through the heat exchange between the circulating cooling medium and the external ambient air in the water-to-air heat exchanger 2.

[0036] 2. The system is also equipped with a complete operation monitoring and control system to ensure that the circulating cooling water system can achieve long-term stable and safe operation.

[0037] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A closed-loop cooling water system, characterized in that: The invention comprises a circulating cooling water pump, a water-to-air heat exchanger (2), a filter (5), a cooled device, and a degassing tank (6) which are connected in sequence through pipelines. The degassing tank (6) is connected to the circulating cooling water pump pipeline to form a circulation. The pipeline between the degassing tank (6) and the circulating cooling water pump is further connected to a nitrogen pressure stabilizing system.

2. A closed-loop cooling water system according to claim 1, characterized in that: Antifreeze containing ethylene glycol is used as the cooling medium.

3. A closed-loop cooling water system according to claim 2, characterized in that: The nitrogen pressure stabilization system comprises a water replenishment interface (10), an expansion tank (9), and a nitrogen bottle (8) which are connected in sequence. The nitrogen bottle (8) is used to fill the expansion tank (9) with high-purity nitrogen at a stable pressure, thereby maintaining a constant pressure in the pipeline and fullness of the cooling medium, and buffering the volume change of the cooling water caused by temperature change.

4. A closed-loop cooling water system according to claim 3, characterized in that: The circulating cooling water pumps are provided in two units, and are interlocked and connected in parallel.

5. A closed-loop cooling water system according to claim 4, characterized in that: The inlet and outlet of the circulating cooling water pump are provided with flexible joints for vibration reduction.

6. A closed-loop cooling water system according to claim 3, characterized in that: The top of the degassing tank (6) is provided with an automatic exhaust valve to completely exhaust the gas in the cooling water; the degassing tank (6) is provided with an electric heater (7) for adjusting the temperature of the cooling water.

7. A closed-loop cooling water system according to claim 3, characterized in that: The water-to-air heat exchanger (2) is provided with a variable frequency fan and multiple groups of industrial frequency fans, and can control the start and stop of the fans according to the inlet water temperature of the cooled device under different ambient temperatures and heat exchange conditions.

8. A closed-loop cooling water system according to any one of claims 3 to 7, characterized in that: It comprises a pressure / pressure difference monitoring device for monitoring the pressure of the expansion tank (9), the outlet pressure of the circulating water pump, and the pressure difference of the filter (5), and a liquid level monitoring device for monitoring the liquid level of the expansion tank (9).

9. A closed-loop cooling water system according to any one of claims 3 to 7, characterized in that: It includes a circulating water flow monitoring device for monitoring each of the cooled devices.

10. A closed-loop cooling water system according to any one of claims 3 to 7, characterized in that: It comprises a temperature monitoring device for monitoring the inlet and return water temperatures of the main pipe and the return water temperature of each cooled device.

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